Dear intarwebs,

Does anybody know a quick and simple application for Windows that will quickly let me take a screenshot and crop it quickly? (I already have a good one for Mac that works well). It needs to be able to stay in my taskbar without consuming a lot of memory! (I have a crappy laptop, and running a VM and Firefox already drain my limited RAM)

I oftentimes see little UI gems on random sites I'd like to start clipping and storing for future reference, but it becomes such a hassle for me to use Photoshop to do this.

Bonus points if it'll auto-post to Flickr.